Wright N et al. The BROAD study: A randomised controlled trial using a whole food plant-based diet in the community for obesity, ischaemic heart disease, or diabetes. Nature 2016
- Reviews of dietary interventions for weight loss don’t show superiority of one diet over another
- Previous interventions using a whole food plant based diet (WFPB) alone or with exercise have demonstrated reversal of ischemic heart disease, weight loss, improvements in glycemic control, and long-term sustainability.
- Purpose of study was to investigate effectiveness of a 12-week community-based WFPB diet on weight loss (BMI), reduction in cardiovascular risk factors, and quality of life when compared to standard medical care.
- Participants in study were from a general practice in a town in New Zealand that had the highest rates of socioeconomic deprivation, obesity, and type 2 diabetes.
- Inclusion criteria included age 35-70, either obese or overweight as categorzed by BMI, and with a diagnosis of at least one of type 2 diabetes, ischemic heart disease, hypertension, high cholesterol. 65 patients were ultimately included in study.
- Participants followed a low-fat version of a plant-based diet (7-15% total energy from fat). Dietary approach included whole grains, legumes, vegetables, and fruit.
- Participants were advised to eat until full- no caloric restrictions. They were also not encouraged to exercise, but rather focus on dietary intervention. They were also asked to avoid eating refined oils and animal products.
- Primary outcome measures were BMI and cholesterol with secondary outcomes measures of any changes in medication usage, quality of life, and any cardiovascular events or changes in care.
- BMI and weight reduction was statistically significant between groups. BMI reduction was 4.4 at 6 months and 4.2 at 12 months. Weight loss was 12.1 kg at 6 months and 11.5 kg at 12 months
- Changes in cholesterol were not significant at 6 months but post-hoc analysis at 12 months did show a significant between-group difference.
- For cardiovascular risk factors, a reduction in 5 for HbA1c took place at 6 months and 12 months in the intervention group with no changes in the control group. Higher starting A1c correlated with larger reductions.
- Quality of life showed significant improvements in the intervention group at all time points, but especially for nutritional self-efficacy and self-esteem at 6 months
- A WFPB diet is a safe and effective option for weight loss and obtaining some reductions in cholesterol without necessarily increasing exercise. This small study also showed improvements in chronic disease risk factors and quality of life which were largely maintained at 12 months